480 TRYOONID^. 



17. Trygon ukpam. 

 Hemitrygon ukpam, J. Alex. S7n{th, Proc. R. Phys. Soc. Edinh. 1859, 

 p. 64. 



Characters of neiv-horn individuals. — Body 11 inches long and 

 nearly as broad, tail 30 inches. Outline uniformly rounded. Upper- 

 side of the body rough, granular, the granular appeaiance diminisli- 

 ing towards the pectoral fins, whilst the granules become larger 

 and circular in shape towards the mesial line of the fish, which from 

 the posterior half of the body gives indications of larger circular 

 plates or shields ; these become still larger towards the root of the 

 tail, and cease in the mesial line a little beyond it. Beyond the 

 spine a smaller double range of oval-shaped obliquely placed bony 

 scales or granules can be traced along the sides of the tail. Five 

 papillfe at the bottom of the mouth behind the lower teeth. Tail 

 without ridge above, but with a distinct fringe below. — Old ex- 

 amples very rough and spiny above. (Smith.) 



Old Calabar. Attains to a size of four feet in width. 



18. Trygon bennettii. 



Trygon bennettii, Milll. Sf Henle, p. IGO, taf. 62 ; Dum6ril, Elasmobr. 



p. ,o95 

 cavuea, Richards. Ichth. Chin. p. 197. 



Tail with a rather low cutaneous fold along the lowersido, about 

 thrice as long as tho disk, which is about as broad as long. Snout 

 rather pointed, the margins meeting at a right angle. Young ex- 

 amples entirely smooth ; in older ones a tubercle in the middle of 

 the back, which is gradually surrounded by smaller scale-like tu- 

 bercles, extending backwards to the caudal spine. Coloration uni- 

 form. 



Indian and Atlantic Oceans. 



a. Young. China. Presented by J. E. Reeves, Esq. — Typo of the 



species. 



b. Young : skin. India. Presented by T. E. J. Boileau, Esq. 



c. Young. British Guiana. Purchased. 



19. Trygon tuberculata. 



Trygon tuberculatus, Lacep. ii. p. 106, pi. 4. fig. 1 ; Dum^ril, Elas- 

 mobr. p. 605. 



sabina, Lcmerir, Joiirn. Ac. Xat. Sc. Philad. iv. p. 109; Miill. ^ 



Hetile, p. 163 ; Jhnneril, I. c. p. 607. 



gymnura, Miill. in Erntan'.-i Rci.fe, p. 2-5, taf. 13. 



osteosticta, Miill. I. c. p. 25, taf. 14. 



Tail with a distinct cutaneous fold below, a very loyr upper fold 

 being as frequently present as absent. IVie tail is more than ttvice 

 as lowj as the disk. Snout pointed and rather produced. A series 

 of spinous tubercles, each with the point directed backwards, runs 

 from the scapulary region to the caudal spine ; older individuals 

 having the upporside of the head and trunk more or less oxten- 



